Scaling PassivHaus

This Article was originally written for the PassivHaus Magazine in March 2014

PassivHaus works. If you are reading this, you probably already know that, but why doesn’t everyone do it? There are around 250-300 certified PassivHaus buildings in the UK. Or to put it another way, less than 0.25% of the homes built per year in the UK are built to this standard.

It’s too expensive…

The late Howard Liddell, an outstanding architect of low energy buildings, had a mantra that the cost of the building had nothing to do with its low energy characteristics, but that it reflected the thought through design and subsequent implementation of that design. There are a number of projects that have already been delivered within the same budget as a non-PassivHaus building. There are also other projects where the costs have been incredibly high – however, the same can be said for any type of building!

It’s too hard…

PassivHaus demands a rigorous and robust design and construction process with an unrelenting attention to detail. When put in the traditional design and build process, the compromises begin. To win on a design and build contract, the contractor is forced to go through a ‘value engineering’ process which is aimed at reducing the cost of construction to be the lowest price in the tender process. The easiest way to do that is to substitute products from the original specification, but this is counter-intuitive when it comes to PassivHaus. This process is directly at odds with the control required to provide performance necessary for low energy buildings.

You can’t value engineer physics…

If we accept that the control of the process is paramount, we have to change the way we procure. There are a number of enlightened clients that have changed to a contract where that control can continue throughout the process. If we are to truly scale PassivHaus, construction clients need to be aware that the way they procure buildings is a real barrier to operational efficiency.

It has already been said by so many in the industry, but we really do need to join up the dots between the construction and operation costs; everyone in the industry has a responsibility to educate clients in this. Research carried out by Constructing Excellence shows that for every £1m spent on construction, £5m is spent on operation and maintenance with energy as the single biggest contributor to ongoing costs. PassivHaus offers a real opportunity to reduce that ratio.

About the Author

John Cave FRSA MIET is Sustainability Director for EH Smith (Builders’ Merchants) Ltd, one of the largest privately owned Builders’ Merchants in the UK. EH Smith have been involved in material specification and supply on numerous PassivHaus projects since 2008 including self-build projects, scaled social housing, schools and commercial buildings.For more information contact 0845 070 3406, or visit sustainablebuildingmaterials.co.uk